Design of a Reverse Osmosis Desalination Plant Powered by Renewables for a Small Mediterranean Island

Water shortage is one of the main problems for small, isolated islands, especially in the Mediterranean Sea. Water supply in those areas relies on maritime transport through tanker ships, especially during periods of high demand. However, this solution is unsuitable for isolated islands due to the high costs and environmental impact. This study aims to assess the feasibility of powering a desalination facility in a remote location with renewable energy sources to assess the potential cost savings and reduction of greenhouse gas emissions compared to the current supply mechanisms. To this end, the Greek island of Tilos is selected as a case study due to its high unexploited renewable energy production during winter months. The study hypothesizes using a seawater reverse osmosis (SWRO) unit to increase the sustainability of the water supply and promote the island's self-sufficiency. Two control strategies have been adopted, simulating a demand-driven and a renewable production-driven scenarios. Results show a levelized cost of water that ranges between 1 and 2 €/m3, which is consistent with the average cost for the existing desalination plants in Grece. The adoption of a SWRO facility coupled with water storage systems results always in a more cost-effective solution than maritime transport, leading also to a relevant reduction of the environmental impact.